In a skillet over medium heat, melt the butter. Add the diced pineapple and brown sugar, stirring occasionally. Cook for about 5-7 minutes until the pineapple is caramelized and golden brown. Remove from heat and let cool slightly.

In a blender, combine the caramelized pineapple, yogurt, milk, honey, ground cardamom, and vanilla extract. Blend until smooth and creamy. If you prefer a chilled lassi, add ice cubes and blend again until frothy.

Taste and adjust sweetness by adding more honey if desired.

Pour the lassi into glasses and serve immediately, garnished with a sprinkle of cardamom or a few pineapple chunks if desired.